I wrote in my book Mindhacker, "Of course, time is time everywhere, but one of the surest ways to vault out of Earthly timekeeping considerations — and thereby gain a wider viewpoint — is to develop a clock and calendar for another world. As Lance Latham points out, because you can’t rely on comfortable Earthly constants like 365, 24, and 60, developing a calendar for another planet can be a self-test for understanding calendrical concepts... why not try designing a calendar for Saturn; one of the moons of Jupiter, such as Europa; or the asteroid Ceres?"

I took my own advice and developed this timekeeping system. Because it has an ocean of water, Europa is one of the more likely spots in the solar system to have developed life, so one day, humans may establish a scientific base there. This system was developed against that day. I'm not vain enough to believe such explorers would actually use my clock and calendar, but they were fun to imagine.